Pulsatillae radix is a dried root of Pulsatilla species belonging to the Ranunculaceae family (Ki Hwan Bae, Korean Medicinal Herbs, 1999). According to the Chinese medicine, Pulsatillae radix is known to have effects of removing heat from the blood and detoxifying. It has also been used as anti-inflammatory, astringent, hemostatic and antidiarrhea agents, and for the treatment of hematochezia, malaria, nosebleed, and bleeding from tooth. Its flower is called as Pulsatillae Flos, and used for the treatment of malaria, or smallpox. Its leaf is called as Pulsatillae Folium, and used for treatment of waist pain, edema, or heart pain. In addition, decoction of Pulsatillae radix was reported to have an antibacterial effect against amoebic dysentery, and a pesticidal effect against Trichomonas.
Pulsatillae radix contains about 9% of saponins, and such ingredients as protoanemonin, anemonin, ranunculin, hederagenin, betulinic acid, and oleanolic acid derivatives and their glycosides have been isolated therefrom by now as represented by the following formula (II):
Protoanemonin anemonin Ranunculin Hederagenin; R = H Hederagenin 3-O-b-D- glucopyranoside; R = glc Patensin; R = glc-gal 23-Hydroxy- betulinic acid;nl R1 = R3 H, R2 = OH Pusatillic acid; R1, R2 = O, R3 = H Pusatilloside A; R1= R3 = H, R2 = ara Pusatilloside B; R1 = H, R2 = OH, R3 = glc-glc
The above ingredients have not yet been extensively studied for their pharmacological effects, but protoanemonin was reported to have mitotoxicity (Vonderbank, F., Pharmazie 5, 210, 1950). Li, et al. (Li, R. Z., et al., Yao Hsuch Hsuch Pao. 28, 326 31, 1993) also reported that ranunculin has cytotoxicity against KB cells, by inhibition of DNA polymerase.
Hederagenin 3-O-α-L-rhamnopyranosyl(1→2)-[β-D-glucopyranosyl(1→4)]-α-L-arabinopyranoside was isolated from Pulsatilla cerna and P. koreana by Shimizu, et al. (Chem. Pharm. Bull., 26, 1666, 1978); from P. chinensis by Yoshihiro, et al. (J. Nat. Pro., 62, 1279, 1999); and from Serjania salzmanniana Schlecht by Ekabo, et al. (J. Nat. Prod., 59, 431, 1996). Kang, et al. (Arch. Pharm. Res., 12(1), 42-47, 1989) also isolated it from P. koreana, and reconfirmed its structure. Yoshihiro, et al. reported that hederagenin and oleanolic acid derivatives showed cytotoxicity against HL-60 human leukemia cells in the above article. They reported that hederagenin 3-O-α-L-rhamnopyranosyl(1→2)-[β-D-glucopyranosyl(1→4)]-α-L-arabinopyranoside isolated from Chinese Pulsatillae radix (Pulsatilla chinensis) had week cytotoxicity, i.e. 3.8 μg/ml of ED50, against HL-60 cells. However, most of saponins and many kinds of natural products commonly show such level of cytotoxicity, and thus, the above compound cannot be said to have antitumor activity based thereon. Therefore, it has never been known that hederagenin 3-O-αL-rhamnopyranosyl(1→2)-[β-D-glucopyranosyl(1→4)]-α-L-arabinopyranoside has antitumor activity, particularly, against solid tumors.